This proposal requests funds for the purchase of a scanning electron microscope with backscattered electron imaging detector. The instrument will be placed in and maintained by the School of Biological Sciences Electron Microscope Facility. The major users in this request are members of four departments and three Schools. All of them possess external funding and all rely on electron microscopy as a major research technique. The problems studied are varied. They include studies of neuronal differentiation, regeneration and communication; ultrastructural analysis of healthy and perturbed respiratory epithelia: anaylsis of highly crosslinked organic network polymers: structural analysis of senile plaque cores on Alzheimer's brains: as well as in situ localization of specific DNA sequences along chromosomes. The instrument requested will therefore support research in a variety of areas of basic research in biology, medicine, and chemistry. P01=P01HD26927 This Program Project application proposes a broad based biobehavioral investigation of the antecedents of stereotyped, self-injurious, and aggressive behavior (aberrant behavior). Each of the four projects is aimed toward isolating antecedents of aberrant behavior and developing procedures for reducing or eliminating aberrant behavior. Three of the projects (Projects I, II, and III) are aimed toward isolating antecedents that affect the rate of aberrant behavior among individuals with retardation and then evaluating treatments or manipulations designed to reduce or eliminate such behavior. Each of these three highly related projects takes a slightly different approach. Project 1 (Saunders & Spradlin) working with individuals with severe and profound retardation will analyze the daily routines of the educational and vocational environments to determine what types of instruction, groupings, and routines result in high and low levels of aberrant behavior. Then they will redesign environments to minimize antecedents that evoke aberrant behaviors. Project II (Baer & Petersen) working with a slightly higher functioning population will also be seeking social antecedents that evoke aberrant behavior. However, their approach is to, through desensitization and self-control procedures, retrain the persons to behave in a more appropriate productive manner when encountering these antecedents. Project III (Rast, Menon, Schroeder, Tessel, & Williams) also are interested in the social antecedents that affect the rates of aberrant behavior, but they are also focusing on neurochemical effects of neuroleptic and anti-epileptic drugs that may determine rates. Their work will lead to ways of determining and implementing optimal drug treatments for reducing aberrant behavior while increasing productive behavior. Project IV (Tessel & Schroeder) will develop animal models of the development, maintenance and pharmaceutical treatments of aberrant behaviors. Their work extends the research of the program into isolating genetic and early biological antecedents of aberrant behaviors and providing a basis for prevention of the development of aberrant behavior. In summary, this Program Project should make possible prevention of many forms of aberrant behavior, as well as the reduction of aberrant behavior once it has developed.